A method for filling a recessed feature of a substrate includes a) at least partially filling a recessed feature of a substrate with tungsten-containing film using at least one of chemical vapor deposition (CVD) and atomic layer deposition (ALD); b) at a predetermined temperature, using an etchant including activated fluorine species to selectively etch the tungsten-containing film more than an underlying material of the recessed feature without removing all of the tungsten-containing film at a bottom of the recessed feature; and c) filling the recessed feature using at least one of CVD and ALD.
Legal claims defining the scope of protection, as filed with the USPTO.
1. A method for filling a recessed feature of a substrate, comprising: a) providing a substrate including a dielectric layer, a liner/barrier layer, and a recessed feature; b) at least partially filling the recessed feature of the substrate with tungsten-containing film using at least one of chemical vapor deposition (CVD) and atomic layer deposition (ALD); c) at a predetermined temperature less than or equal to 150° C., using an etchant including activated fluorine species to selectively etch the tungsten-containing film in the recessed feature at an etch rate that is higher than an etch rate of the liner/barrier layer, wherein the etching exposes at least a portion of the liner/barrier layer in the recessed feature and does not remove all of the tungsten-containing film at a bottom of the recessed feature; d) repeating (b) and (c) one or more times, wherein, during a first iteration of (c), the etching removes the tungsten-containing film in the recessed feature to a level that is below a field region of the dielectric layer; and e) filling the recessed feature using at least one of CVD and ALD.
2. The method of claim 1 , wherein (b) includes filling the recessed feature with the tungsten-containing film such that an opening of the recessed feature is pinched off.
3. The method of claim 1 , wherein (b) includes filling the recessed feature with the tungsten-containing film such that an opening of the recessed feature is closed and overburden is deposited on a field of the substrate.
4. The method of claim 1 , wherein (c) is performed in one of a CVD chamber and an etch chamber.
5. The method of claim 1 , wherein the underlying material includes a liner/barrier layer.
6. The method of claim 2 , wherein the liner/barrier layer includes one of titanium and tantalum.
7. The method of claim 2 , wherein the liner/barrier layer includes one of titanium, titanium nitride, tantalum nitride, and TiC x N x .
8. The method of claim 1 , further comprising performing chemical mechanical planarization (CMP) of the substrate after (e).
9. The method of claim 1 , wherein the predetermined temperature is less than or equal to 100° C.
10. The method of claim 1 , wherein the predetermined temperature is less than or equal to 50° C.
11. The method of claim 5 , wherein the liner/barrier layer includes an overhang that creates a pinch point at an opening of the recessed feature.
12. The method of claim 1 , further comprising adding one or more of nitrogen, oxygen, hydrogen, helium, argon, or fluorine to slow etching of the liner/barrier layer.
13. The method of claim 5 , further comprising oxidizing the liner/barrier layer prior to (b).
14. The method of claim 1 , wherein the level is closer to the bottom of the recessed feature than to the field region of the dielectric layer after the first iteration of (c).
15. A method for filling a recessed feature of a substrate, comprising: a) providing a substrate including a dielectric layer, a liner/barrier layer, and a recessed feature, b) oxidizing the liner/barrier layer; c) at least partially filling the recessed feature of the substrate with tungsten-containing film using at least one of chemical vapor deposition (CVD) and atomic layer deposition (ALD); d) at a predetermined temperature less than or equal to 150° C., using an etchant including activated fluorine species to selectively etch the tungsten-containing film in the recessed feature at an etch rate that is higher than an etch rate of the liner/barrier layer, and wherein the etching removes the tungsten-containing film in the recessed feature, and the etching exposes at least a portion of the liner/barrier layer in the recessed feature and does not remove all of the tungsten-containing film at a bottom of the recessed feature; e) repeating c) and d) one or more times, wherein during a first iteration of (d) the etching removes the tungsten-containing film in the recessed feature to a level that is below a field region of the dielectric layer; and f) at least partially filling the recessed feature using at least one of CVD and ALD.
16. The method of claim 15 , wherein the level is closer to the bottom of the recessed feature than to the field region of the dielectric layer after the first iteration of (d).
Cooperative Patent Classification codes for this invention. Click any code to explore related patents in that topic.
June 28, 2012
November 11, 2014
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